September 18, 2017

The 250,000 Pound Monster

(from the archives October 2015?)

I just learned that there is actually a monster under my bed. Well, to be a little more precise, it's about a mile or so down the road from me in Torrance, CA. I didn't want to be afraid of this monster, but I can't honestly say that I'm not afraid. That's because of all I've learned about risk in the past few years by reading Taleb. It's very simple. There are over 10,000 tons of modified hydrofluoric acid sitting in a fancy tank in the oil refinery in my neighborhood. Last year, that fancy tank just missed getting ripped wide open in an explosion that blew a 40 ton chunk of machinery that landed 3 feet away. Scary monster? You bet.

Of course, everybody wants to bet. You can guess who is betting which way because it has come down to a war of will and words between a whole lot of anxious people. You see, Exxon Mobil, who owned the refinery when it blew up basically got the hell out of Dodge. Their bet was to sell the refinery to a company called PBF who is not nearly as well-financed. A local group of Torrance residents formed a group called TRAA, and they are betting that they can get the fancy acid tanks converted to something a lot more safe. The City of Torrance seems to be hedging their bets. On the one hand they'd like to say that everything is OK, on the other hand they may say something else in private. Of course some of us have just realized we may be betting our lives. But what, you may ask, is the big special deal about a fancy acid tank? Well, nothing really, it's more about the choice of acid.

If you want to make high octane gasoline, and who doesn't want to make that, right?; you have to use a fairly well-known (to chemical engineers) process called alkylation. Alkylation requires some serious acid, and there are only two acids that are strong enough to make the good stuff. One is hydrofluoric acid, which the Torrance Refinery uses, and the other is sulfuric acid. So it's HF vs H2SO4, just like back in high school chemistry. No actually that was HCl. HF they don't allow in high school chemistry. In fact, most chemists are scared of the stuff, at least all of the chemists I could find on YouTube. But here's the extraordinarily dangerous part, as opposed to the moderately frightening aspect of HF stuff that you see on YouTube. The boiling point of HF is just below 70 degrees Fahrenheit. Used in the refinery at higher temperatures, it's a gas. Gas as in, blows whichever way the wind goes if it gets out. Now you know why I'm afraid of this monster. If it gets out, it can't be controlled.

So in addition to YouTubery, I've got some Wikistuff. Check this out:

In a standard oil refinery process, isobutane is alkylated with low-molecular-weight alkenes (primarily a mixture of propene and butene) in the presence of a Bronsted acid catalyst, either sulfuric acid or hydrofluoric acid.[4] In an oil refinery it is referred to as a sulfuric acid alkylation unit (SAAU) or a hydrofluoric alkylation unit, (HFAU). Refinery workers may simply refer to it as the alky or alky unit. The catalyst protonates the alkenes (propene, butene) to produce reactive carbocations, which alkylate isobutane. The reaction is carried out at mild temperatures (0 and 30 °C) in a two-phase reaction. Because the reaction is exothermic, cooling is needed: SAAU plants require lower temperatures so the cooling medium needs to be chilled, for HFAU normal refinery cooling water will suffice. It is important to keep a high ratio of isobutane to alkene at the point of reaction to prevent side reactions which produces a lower octane product, so the plants have a high recycle of isobutane back to feed. The phases separate spontaneously, so the acid phase is vigorously mixed with the hydrocarbon phase to create sufficient contact surface.

Notice the point where they say exothermic. I remember that from high school chemistry. That means if something breaks, then left alone you get higher temperatures and pressures. Imagine a shark; if he stops swimming, he explodes. So you've got to keep some machines running all the time. That's what makes the tank so fancy. So what do you want to bet that the fancy tank's machines don't sleep? What about the machine minders? Don't they sleep? I'm sure there are some work rules about that. Hey. I found some rules: HF is registered as toxic under SARA Title III section 313.

Now let's dig into the weeds a little further. There's a difference between HF and modified HF. The modification is there because HF floats, whereas H2S04 does not. And this is the thing with HF, what makes it the good stuff is it's basic beastie-ass nature. You don't need so much of it because it reacts like a boss, whereas the sulfuric acid, well you need more. And at a measly $2000 per metric ton, the trucks keep rolling in to the refinery. (It's not like somebody's going to build an HF pipeline). Anyway, you may see MHF right next to HF, and people betting on the fancy tanks will tell you that there's a significant difference between MHF and HF. So basically the M is for modified, and that's some kind of additive that you mix in to the HF in an attempt to make it less floaty. But the M also makes it less beastie too. So it turns out that once upon a time, by consent decree, the refinery was order to add 30% M. It turned out that that formula of MHF was not beastie enough to run the refinery's process. They watered it down too much. So a decision was made to change the MHF mix down to 10%. So now it's more like mHF than MHF. Or basically 90% HF rather than 70%. 90% HF is basically HF. Just like 90% octane is basically premium gas. Well, add 1% more it is, but nobody sells 70% octane gas. That's too watered down. And that's what the guys at the refinery said about their MHF. So, yeah, they want to tell everybody that MHF is safe, but they spiked their own formula, so...

H2SO4 on the other hand, doesn't float away on the breeze. In fact it's kind of syrupy.

Now you may remember, Cobb readers, that when the refinery went kaboom. I immediately ran out to see what was going on. If the HF had gotten out, I would have been dead. So that's why I'm kind of pissed off to actually look in a bit closer to this toilet and smell the smell of something smelly.

Comments

The 250,000 Pound Monster

(from the archives October 2015?)

I just learned that there is actually a monster under my bed. Well, to be a little more precise, it's about a mile or so down the road from me in Torrance, CA. I didn't want to be afraid of this monster, but I can't honestly say that I'm not afraid. That's because of all I've learned about risk in the past few years by reading Taleb. It's very simple. There are over 10,000 tons of modified hydrofluoric acid sitting in a fancy tank in the oil refinery in my neighborhood. Last year, that fancy tank just missed getting ripped wide open in an explosion that blew a 40 ton chunk of machinery that landed 3 feet away. Scary monster? You bet.

Of course, everybody wants to bet. You can guess who is betting which way because it has come down to a war of will and words between a whole lot of anxious people. You see, Exxon Mobil, who owned the refinery when it blew up basically got the hell out of Dodge. Their bet was to sell the refinery to a company called PBF who is not nearly as well-financed. A local group of Torrance residents formed a group called TRAA, and they are betting that they can get the fancy acid tanks converted to something a lot more safe. The City of Torrance seems to be hedging their bets. On the one hand they'd like to say that everything is OK, on the other hand they may say something else in private. Of course some of us have just realized we may be betting our lives. But what, you may ask, is the big special deal about a fancy acid tank? Well, nothing really, it's more about the choice of acid.

If you want to make high octane gasoline, and who doesn't want to make that, right?; you have to use a fairly well-known (to chemical engineers) process called alkylation. Alkylation requires some serious acid, and there are only two acids that are strong enough to make the good stuff. One is hydrofluoric acid, which the Torrance Refinery uses, and the other is sulfuric acid. So it's HF vs H2SO4, just like back in high school chemistry. No actually that was HCl. HF they don't allow in high school chemistry. In fact, most chemists are scared of the stuff, at least all of the chemists I could find on YouTube. But here's the extraordinarily dangerous part, as opposed to the moderately frightening aspect of HF stuff that you see on YouTube. The boiling point of HF is just below 70 degrees Fahrenheit. Used in the refinery at higher temperatures, it's a gas. Gas as in, blows whichever way the wind goes if it gets out. Now you know why I'm afraid of this monster. If it gets out, it can't be controlled.

So in addition to YouTubery, I've got some Wikistuff. Check this out:

In a standard oil refinery process, isobutane is alkylated with low-molecular-weight alkenes (primarily a mixture of propene and butene) in the presence of a Bronsted acid catalyst, either sulfuric acid or hydrofluoric acid.[4] In an oil refinery it is referred to as a sulfuric acid alkylation unit (SAAU) or a hydrofluoric alkylation unit, (HFAU). Refinery workers may simply refer to it as the alky or alky unit. The catalyst protonates the alkenes (propene, butene) to produce reactive carbocations, which alkylate isobutane. The reaction is carried out at mild temperatures (0 and 30 °C) in a two-phase reaction. Because the reaction is exothermic, cooling is needed: SAAU plants require lower temperatures so the cooling medium needs to be chilled, for HFAU normal refinery cooling water will suffice. It is important to keep a high ratio of isobutane to alkene at the point of reaction to prevent side reactions which produces a lower octane product, so the plants have a high recycle of isobutane back to feed. The phases separate spontaneously, so the acid phase is vigorously mixed with the hydrocarbon phase to create sufficient contact surface.

Notice the point where they say exothermic. I remember that from high school chemistry. That means if something breaks, then left alone you get higher temperatures and pressures. Imagine a shark; if he stops swimming, he explodes. So you've got to keep some machines running all the time. That's what makes the tank so fancy. So what do you want to bet that the fancy tank's machines don't sleep? What about the machine minders? Don't they sleep? I'm sure there are some work rules about that. Hey. I found some rules: HF is registered as toxic under SARA Title III section 313.

Now let's dig into the weeds a little further. There's a difference between HF and modified HF. The modification is there because HF floats, whereas H2S04 does not. And this is the thing with HF, what makes it the good stuff is it's basic beastie-ass nature. You don't need so much of it because it reacts like a boss, whereas the sulfuric acid, well you need more. And at a measly $2000 per metric ton, the trucks keep rolling in to the refinery. (It's not like somebody's going to build an HF pipeline). Anyway, you may see MHF right next to HF, and people betting on the fancy tanks will tell you that there's a significant difference between MHF and HF. So basically the M is for modified, and that's some kind of additive that you mix in to the HF in an attempt to make it less floaty. But the M also makes it less beastie too. So it turns out that once upon a time, by consent decree, the refinery was order to add 30% M. It turned out that that formula of MHF was not beastie enough to run the refinery's process. They watered it down too much. So a decision was made to change the MHF mix down to 10%. So now it's more like mHF than MHF. Or basically 90% HF rather than 70%. 90% HF is basically HF. Just like 90% octane is basically premium gas. Well, add 1% more it is, but nobody sells 70% octane gas. That's too watered down. And that's what the guys at the refinery said about their MHF. So, yeah, they want to tell everybody that MHF is safe, but they spiked their own formula, so...

H2SO4 on the other hand, doesn't float away on the breeze. In fact it's kind of syrupy.

Now you may remember, Cobb readers, that when the refinery went kaboom. I immediately ran out to see what was going on. If the HF had gotten out, I would have been dead. So that's why I'm kind of pissed off to actually look in a bit closer to this toilet and smell the smell of something smelly.